PB97-964110
EPA/541/R-97/112
January 1998
EPA Superfund
Record of Decision:
Wright-Patterson Air Force Base, OU 2
Dayton, OH
9/30/1997
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UNITED STATES AIR FORCE
INSTALLATION RESTORATION PROGRAM
WRIGHT-PATTERSON AIR FORCE BASE
88™ AIR BASE WING
WRIGHT-PATTERSON AIR FORCE BASE, OHIO
RECORD OF DECISION
FOR
SPILL SITES 2, 3, AND 10 WITHIN "
OPERABLE UNIT 2
WRIGHT-PATTERSON AIR FORCE BASE, OHIO
Wright-Pattersoo MB
SEPTEMBER 1997
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INSTALLATION RESTORATION PROGRAM
RECORD OF DECISION
FOR
SPILL SITES 2, 3, AND 10 WITHIN
OPERABLE UNIT 2
AT
WRIGHT-PATTERSON AIR FORCE BASE, OHIO
SEPTEMBER 1997
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CONTENTS
LISTOFFIGURES v
LISTOFTABLES v
ACRONYMS AND ABBREVIATIONS vi
1. THE DECLARATION 1
1.1 SITE NAME AND LOCATION 1
12 STATEMENT OF BASIS AND PURPOSE 1
13 ASSESSMENT OF THE SITE 1
1.4 DESCRIPTION OF THE SELECTED REMEDY 1
1.5 STATUTORY DETERMINATION 2
2. DECISION SUMMARY 4
2.1 SITE NAME, LOCATION, AND DESCRIPTION 4
2.1.1 Site Name and Location 4
2.1.2 Site Description 4
2.1.3 Ecology 7
2.1.4 Demography and Land Use 8
22 SITE HISTORY AND ENFORCEMENT 8
2.2.1 Site History 8
2.2.2 Enforcement 9
23 HIGHLIGHTS OF COMMUNITY PARTICIPATION 10
2.4 SCOPE AND ROLE OF SPILL SITES 2,3. and 10 10
2.5 SUMMARY OF SITE CHARACTERISTICS „ 11
2.5.1 Summary of Site Soil Characteristics 11
2.5.2 Summary of Site Groundwater Characteristics 11
2.6 SITE RISKS 13
2.6.1 Human Health Risk. 13
2.6.2 Ecological Risk 18
2.7 IDENTIFICATION OF CONTAMINANTS NEEDING REMEDIATION 18
2.8 DESCRIPTION OF ALTERNATIVES _ 18
2.8.1 Alternative GW1 20
2.8.2 Alternative GW2A 20
2.8.3 Alternative GW2B 22
2.8.4 Alternative GW2C 25
2.8.5 Alternative GW3C 26
2.8.6 Alternative GW4C 28
2.8.7 Alternative GW5C 30
2.8.8 Alternative GW6 31
2.9 SUMMARY OF THE COMPARATIVE ANALYSIS OF ALTERNATIVES 33
2.9.1 Threshold Criteria 33
2.9.2 Primary Balancing Criteria 34
2.9.3 Modifying Criteria 35
2.10 THE SELECTED REMEDY 35
2.11 STATUTORY DETERMINATION 36
2.11.1 The Selected Remedy is Protective of Human Health and the Environment 36
WPAFB Draft Record of Decision for Spill Sites 2,3 and 10 Ui
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2.11.2 The Selected Remedy Complies with Applicable or Relevant
and Appropriate Requirements 37
2.11.3 The Selected Remedy is Cost Effective 37
2.11.4 The Selected Remedy Uses Permanent Solutions and Alternative Treatment Technologies to
the Maximum Extent Practicable 37
2.12 DOCUMENTATION OF NO SIGNIFICANT CHANGES 38
Appendix A: Administrative Record
Appendix B: Responsiveness Summary
WPAFB Draft Record of Decision for Spill Sites 2,3 and 10 iv
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FIGURES
1. Location of Wright-Patterson Air Force Base
2. Site Location Map
3. BTEX Contamination in Soil During July 31 to December 7,1992
4. BTEX Contamination in Groundwater During December 1 to 16,1992
5. Overview of the Feasibility Study Process
6. Conceptual Plan for Soil Bioventing/Bioslurper/Vapor Extraction Wells
7. Conceptual Plan Showing Location for Groundwater Collection and Treatment System
8. Conceptual Plan for Groundwater Extraction Wells, Soil Bioventing Wells, and Groundwater
Treatment System.
9. Proposed Vapor Extraction and Air Sparging Wells
TABLES
1. Human Health Risk Summary at the POL Storage Area Vicinity Sites
2. Summary of Remedial Alternatives
3. Summary of Applicable or Relevant and Appropriate Requirements
WPAFB Draft Record of Decision for Spill Sites 2,3 and 10
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ACRONYMS AND ABBREVIATIONS
ARAR applicable or relevant and appropriate requirements
BMP Basewide Monitoring Program
BTEX benzene, toluene, ethylbenzene, and xylenes
BUSTR Bureau of Underground Storage Tank Regulations
CERCLA Comprehensive Environmental Response, Compensation, and Liability Act
CT central tendency
DO dissolved oxygen
FFA Federal Facilities Agreement
FS Feasibility Study
HEAST Health Effects Assessment Summary Tables
HQ Hazard Quotient
IRIS Integrated Risk Information System
IRP Installation Restoration Program
MCL maximum contaminant level
NCP National Oil and Hazardous Substances Pollution Contingency Plan
NGVD National Geodetic Vertical Datum of 1929
NPL National Priorities List
O&M operations and maintenance
OEPA Ohio Environmental Protection Agency
OU Operable Unit
PAH polycyclic aromatic hydrocarbon
POL petroleum, oil, and lubricants
RfC reference concentration
RfD reference dose
RI remedial investigation
RME reasonable maximum exposure
ROD Record of Decision
SVOC semivolatile organic compound
TCE trichloroethene
USEPA U.S. Environmental Protection Agency
VLEACHSM Vadose Zone LEACHing and Saturated zone Mixing model
VOC volatile organic compound
WPAFB Wright-Patterson Air Force Base
WPAFB Draft Record of Decision for Spill Sites 2,3 and 10
VI
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la. THE DECLARATION-USAF
laJ SITE NAME AND LOCATION
Spoil Sites 2, 3, and 10, Operable Unit 2
Wright-Patterson Air Force Base
Greene and Montgomery counties, Ohio.
1x2 STATEMENT OF BASIS AND PURPOSE
This Record of Decision (ROD) doaimftit presents the selected remedial action to reduce the
risks posed by subsurface soil andgroundwater at Operable Unit 2 Spill Sites 2, 3, and 10 in the
Petroleum. Oil, and Lubricants Area vidnhy at Wright-Patterson Air Force Base (WPAFB). The
selection of the remedial action was conducted in accordance with the Comprehensive
Environmental Response. Compensation, and Liability Act (CERCLA) of 1980 as amended by
die Superfund Amendments and Reamborization Act of 1986, and, to the extent practicable, the
National Oil and H*"*xff"K Substances Pollution Contingency Plan (NCP). This decision is
based on the Administrative Record for the site. AU documents, ooirespondenoe, and other
resources that comprise the Administrative Record upon which this decision is based ate
identified in Appendix A.
The lead agency. WPAFB. supports die selected remedy at tins site.
Ia3 ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous substances from this site, if not addressed by
implementing the response action selected in mis ROD. may present an imminent and substantial
endaneBiment to public health, welfare, or the environment.
Itwl DESCRIPTION OF THE SELECTED REMEDY
This ROD documents the selected remedy for subsurface soil and grotmdwater contamination at
Spm Sites 2, 3. and 10, wbicbne part of Operable Unit (OU) 2. OU 2 represents one component
of a comprehensive environmental mvestigatioB aad cleanup presently being performed under
the Installation Restoration Program (IRP) at WPAFB. The IRP has divided the Base into II
OUs, each with several IRP sites located in close proximity to each other. In most cases, the
Remrriial Investigations (RIs) conducted at the OUs addressed only the sou
.
Gtoundwang; surface water, and yrfinvm flowing from these areas wfll be monitored and
p P»«MH«III
Three RODs have been issued as a result of the RIs at WPAFB. These are the "On-Somce" and
-^Dflf-Sowce" RODs for OU land the No Action ROD for sofl at 21 IRP sites. The No Action
gQP aAhBMfte mil at rim$ t&ysj WPAfP, jpelndmg S fftyg from Q^J 1\ tiiE CfflJ md Chcmj«3lll
Storage Area. Temporary Coal Storage Pfle, Long-Tern Coal Storage Area. Burial She 1. and
die Building 89 Coal Storage Pfle. In addition, several IRP sites have foregone me traditional
Feasibifity Study (FS) process and are being addressed with presumptive remedies.
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Tlie select^ icfli^ for sofasurfscescd and grooDdwaierot Spill Sites 2, 3, and 10 in die
Petroleum Ofl and Lubricants (POL) Storage Area vicinity is:
in situ biodfcgiadau'on of contaminants in subsurface soil.
O&M of existing recovery systems,
mstinraonal controls, and
SOU
Thftte actions addmreifr* pn»**ti«l pfJiwJjxIrtiTMfc prxarf hy eflmamtnanr* m rtw
and gronndwaier at Spill Sites 2, 3, and 10.
luJS STATUTORY DETERMINATION
Tfce selected remedy is protective of human health aad the environment, complies with federal
and state requirements that are legally applicable or relevant and appropriate to the remedial
and is cost-effective. This remedy uses permanent solutions and alternative treatment to
the maximum extent practicable. The selected tena^ satisfies the statutory preference for
oeatment as a pnncipal element even though the treatment occois passively and naturally.
Mechanical treatment of the groondwater was not selected became (1)
water beneath the spill site has the capacity to biodegrade the hydzocarbons before a
potential receptor can be reached and (2) insdnxtional controk are already in place to prevent
exposure to snbsuxf ace soiL Additionally, sappkmentai sampfing conducted in May 1997
indicated that m-smx biodegtadation and natural attenuation processes are elfe<»vely occurring
in soil and groundwater, respectively.
Because the remedy win result in the conumed presence of hazadoos substances on the site
above healm-based levels, a review will be conducted within 5 years of comrnencement of the
it9n*Ai*1 action to ensure the remedy continues to provide mfrypinT'? protection of frf»r""» health
and the environment in accordance with NCP Section 300.430 (fX^Xii). This 5 year review win
be performed as part of tfaeBasewide Monitoring Program.
SB>801997
GEORGE TjBABBZTT
General, USAF
Commander
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Ib. THE DECLARATION - USEPA
lb.1 SITE NAME AND LOCATION
Spill Sites 2,3, and 10, Operable Unit 2
Wright-Patterson Air Force Base
Greene and Montgomery counties, Ohio.
lb^ STATEMENT OF BASIS AND PURPOSE
This Record of Decision (ROD) document presents the selected remedial action to reduce the risks posed
by subsurface soil and groundwater at Operable Unit 2 Spill Sites 2,3, and 10 in the Petroleum, Oil, and
Lubricants Area vicinity at Wright-Patterson Air Force Base (WPAFB). The selection of the remedial
action was conducted in accordance with the Comprehensive Environmental Response, Compensation, and
Liability Act (CERCLA) of 1980 as amended by the Superfund Amendments and Reauthorization Act of
1986, and, to the extent practicable, the National Oil and Hazardous Substances Pollution Contingency Plan
(NCP). This decision is based on the Administrative Record for the site. All documents, correspondence,
and other resources that comprise the Administrative Record upon which this decision is based are
identified in Appendix A.
The U.S. Environmental Protection Agency (USEPA) supports the selected remedy.
Ib3 ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous substances from mis site, if not addressed by implementing the
response action selected in this ROD. may present an imminent and substantial endangerment to public
health, welfare, or the environment
lb.4 DESCRIPTION OF THE SELECTED REMEDY
This ROD documents the selected remedy for subsurface soil and groundwater contamination at Spill Sites
2,3. and 10, which are pan of Operable Unit (OU) 2. OU 2 represents one component of a comprehensive
environmental investigation and cleanup presently being performed under the Installation Restoration
Program (IRP) at WPAFB. The IRP has divided the Base into 11 OUs, each with several IRP sites located
in close proximity to each other. In most cases, the Remedial Investigations (RIs) conducted at the OUs
addressed only the source areas. Groundwater. surface water, and sediment flowing from these areas will
be monitored and addressed under the Basewide Monitoring Program.
Three RODs have been issued as a result of the RIs at WPAFB. These are the "On-Source" and
"Off-Source" RODs for OU 1 and the No Action ROD for soil at 21 IRP sites. The No Action ROD
addresses soil at sites across WPAFB, including 5 sites from OU 2; the Coal and Chemical Storage Area,
Temporary Coal Storage Pile, Long-TermCoal Storage Area, Burial Site 1, and the Building 89 Coal
Storage Pile. In addition, several IRP sites have foregone the traditional Feasibility Study (FS) process and
are being addressed with presumptive remedies.
WPAFB Draft Record of Decision for Spill Sites 2,3 and 10 Ib
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The selected remedy for subsurface soil and groundwater at Spill Sites 2, 3. and 10 in the Petroleum. Oil
and Lubricants (POL) Storage Area vicinity is:
in situ biodegradation of contaminants in subsurface soil,
natural attenuation of contaminants in groundwater,
O&M of existing recovery systems,
institutional controls, and
subsurface soil and groundwater monitoring.
These actions address the potential principal threats posed by contaminants in subsurface soil and
groundwater at Spill Sites 2, 3, and 10.
lb^ STATUTORY DETERMINATION
The selected remedy is protective of human health and the environment, complies with federal and state
requirements that are legally applicable or relevant and appropriate to the remedial action, and is cost-
effective. This remedy uses permanent solutions and alternative treatment to the maximum extent
practicable. The selected remedy satisfies the statutory preference for treatment as a principal element even
though the treatment occurs passively and naturally. Mechanical treatment of the groundwater was not
selected because (1) data indicate the groundwater beneath the spill site has the capacity to biodegrade the
hydrocarbons before a potential receptor can be reached and (2) institutional controls are already in place to
prevent exposure to subsurface soil. Additionally, supplemental sampling conducted in May 1997
indicated that in-situ biodegradation and natural attenuation processes are effectively occurring in soil and
groundwater, respectively.
Because the remedy will result in the continued presence of hazardous substances on the site above health-
based levels, a review will be conducted within 5 years of commencement of the remedial action to ensure
the remedy continues to provide adequate protection of human health and the environment in accordance
with NCP Section 300.430 (Q(4)(ii). This 5 year review will be performed as pan of the Basewide
Monitoring Program.
William E. Muno, Director juperfund Division
U.S. Environmental Protection Agency, Region V
WPAFB Draft Record of Decision for Spill Sites 2,3 and 10 2b
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Ic. THE DECLARATION-OHIO EPA
lc.1 SITE NAME AND LOCATION
Spill Sites 2,3, and 10, Operable Unit 2
Wright-Patterson Air Force Base
Greene and Montgomery counties, Ohio.
IcJ, STATEMENT OF BASIS AND PURPOSE
This Record of Decision (ROD) document presents the selected remedial action to reduce the risks posed
by subsurface soil and groundwater at Operable Unit 2 Spill Sites 2,3, and 10 in the Petroleum, Oil, and
Lubricants Area vicinity at Wright-Patterson Air Force Base (WPAFB). The selection of the remedial
action was conducted in accordance with the Comprehensive Environmental Response, Compensation,
and Liability Act (CERCLA) of 1980 as amended by the Superfund Amendments and Reauthorization
Act of 1986, and, to the extent practicable, the National Oil and Hazardous Substances Pollution
Contingency Plan (NCP). This decision is based on the Administrative Record for the site. All
documents, correspondence, and other resources that comprise the Administrative Record upon which
this decision is based are identified in Appendix A.
The Ohio Environmental Protection Agency (OEPA) supports the selected remedy at this site.
IcJ ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous substances from this site, if not addressed by implementing
the response action selected in this ROD, may present an imminent and substantial endangerment to
public health, welfare, or the environment.
lc.4 DESCRIPTION OF THE SELECTED REMEDY
This ROD documents the selected remedy for subsurface soil and groundwater contamination at Spill
Sites 2,3, and 10, which are part of Operable Unit (Oil) 2. OU 2 represents one component of a
comprehensive environmental investigation and cleanup presently being performed under the Installation
Restoration Program (IRP) at WPAFB. The IRP has divided the Base into 11 OUs, each with several
IRP sites located in close proximity to each other. In most cases, the Remedial Investigations (RIs)
conducted at the OUs addressed only the source areas. Groundwater, surface water, and sediment
flowing from these areas will be monitored and addressed under the Basewide Monitoring Program.
Three RODs have been issued as a result of the RIs at WPAFB. These are the "On-Source" and
"Off-Source" RODs for OU 1 and the No Action ROD for soil at 21 IRP sites. The No Action ROD
addresses soil at sites across WPAFB, including 5 sites from OU 2; the Coal and Chemical Storage Area,
Temporary Coal Storage Pile, Long-Term Coal Storage Area, Burial Site 1, and the Building 89 Coal
Storage Pile. In addition, several IRP sites have foregone the traditional Feasibility Study (FS) process
and are being addressed with presumptive remedies.
WPAFB Draft Record of Decision for Spill Sites 2,3 and 10 Ic
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v*.~t.-ji vt.tGr*-.
yrt. c iji<«ae4w4 i-*4i r.«j/6j
The selected remedy for subsurface soil and groundwaxer ai Spill Sixes 2, 3, and 10 in the Petroleum, Oil.
aad Lubricants (POL) Storage Area vicinity is:
in situ tuodegradarion of contaminants in subsurface soil.
natural attenuation of contaminants in groundwater,
OftM of existing recovery systems,
flflfl
subsurface soil ntuf fpfsmita'nfT itvWrni1*^-
Tljese actions address the potential principal threus posed by ajmanrinantstatnesiibsurfacesoaand
groundwater at Spfll Sites 2, 3, and 10.
lc^ STATUTORY DETERMINATION
The selected remedy Uproteqive of hronrohralfh a
er&ctive. TnisietnedyuscspaBnai>niTi>tTrols are
already in place to prevent exposure to sobsorftcesaU. AddiiionaIly,SD|qdenie]aalsanipu^caaduc
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2. DECISION SUMMARY
2.1 SITE NAME, LOCATION, AND DESCRIPTION
2.1.1 Site Name and Location
Spill Sites 2,3, and 10 are located in the POL Area vicinity of WPAFB in southwestern Ohio. The Base
lies in Montgomery and Greene counties, approximately 60 miles north of Cincinnati, SO miles west of
Columbus, just east of the city of Dayton, and adjacent to the city of Fairbom (Fig. 1).
The installation is composed of Wright and Patterson Fields, which are separated by State Route 444.
Wright Field comprises Area B, approximately 2,800 acres; Patterson Held comprises Areas A and C,
approximately 5,711 acres. The spill sites are pan of OU 2: a group of eight sites close together in the
northeastern corner of Patterson Field (Area C). OU 2 sites are Spill Sites 2,3, and 10; the Coal and
Chemical Storage Area; Temporary Coal Storage Pile; Long-Term Coal Storage Area; Burial Site 1; and
the Building 89 Coal Storage Pile. Each site is within 1,000 ft of an adjacent site, and all sites fall within a
rectangular area of approximately 105 acres, although the combined areas of the sites is significantly less.
Spill Sites 2 and 3 are located within the POL Storage Area, approximately 200 ft and 400 ft, respectively,
inside the WPAFB east boundary. Spill Site 10 is approximately 600 ft southwest of the POL Storage Area
and 1,400 ft inside the WPAFB east boundary (Fig. 2).
2.1.2 Site Description
2.1.2.1 Topography
The land surface at WPAFB varies in altitude from approximately 780 to 975 ft above the National
Geodetic Vertical Datum of 1929 (NGVD); land surface at OU 2 varies from approximately 815 to 835 ft
above NGVD. The sites in the POL Storage Area vicinity are relatively flat with only minor topographic
relief. Because of this relatively flat terrain, surface stream and surface water runoff velocities are
typically low, and surface stream sediments tend to accumulate in localized areas downstream from storm
drainage discharges.
2.1.2.2 Geology
The subsurface is composed of six stratigraphic units ranging in age and lithographic type from Paleozoic
age marine limestones and shales to Cenozoic age gravel, sand, silt, and clay of either glacial or fluvial
origins. In ascending stratigraphic order, Unit I bedrock consists of shale interbedded with fossiliferous
limestone. Unit n is composed primarily of unconsolidated lacustrine sediments deposited directly on
bedrock. Unit HI consists of unconsolidated glacial outwash deposits that overlie the lacustrine sediments.
Unit IV is the Discontinuous Till Interval that overlies the lower glacial outwash deposits. Unit V consists
of the upper glacial outwash deposits and usually contains the water table. Unit VI is composed of the
alluvial deposits that occur at the surface. Units n through VI fill the bedrock valley located beneath
WPAFB and the city of Fairborn.
WPAFB Draft Record of Decision for Spill Sites 2,3 and 10
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Patterson Field
Wright Field
SCALE IN MILES
AIM of roPUui Domunf i
OWStudyAra
SCALE: 1'= 3 MILES
DATE: 01-31-97
FIIFNAUF: VICINITV.nr.M
Fig. 1. Location of Wright-Patterson Air Force Base.
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* j. ••* • •,.
v ^-" .-•-'
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€Mf^Wf}^
^ri^M \ ^S'^&V/jky^-*
i trttrH fey WMnrt CcnMlMnH. ltr«h HIT
600
*
SCALE IN FEET
1200
LEGEND
Exlillnt toeannr mi
location e( *lll HtM
|VM« atf llm< »•* fa
FaSlorao* ITM
.
CTflOET ii J
SCALE: 1*= 600' - 0"
DATE! 01-31-97
FILENAME; SITE LOC.DGN
Fig. 2. Site Location Map.
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Soils in Units V and VI are formed in the alluvium and upper glacial outwash deposits within the Mad
River flood plain or terraces. The soil profile consists of a surface layer of dark grayish brown loam
about 11 in. thick; a subsoil interval of dark-brown clay loam to loamy clay to gray clay with a gravel
content of from 5 to 35% extending to a depth of approximately 33 in.; and a substratum composed of
yellowish-brown, very gravelly, loamy sand extending to a depth of approximately 60 in. and grading
into the upper outwash sand and gravel. The reported vertical hydraulic conductivity of surface soil
ranges from 1 to 4 ft per day (ft/day); the measured horizontal hydraulic conductivity in the POL Storage
Area vicinity site subsurface soil ranges from approximately 35 to 205 ft/day at the north end, 0.5 to
190 ft/day in the central portion, and 10 to 190 ft/day in the south end.
2.1.2 J Surface Water
Surface water from OU 2 discharges to the Mad River through Hebble Creek and an extensive storm drain
system. Hebble Creek crosses OU 2 from the eastern edge and adjoins the City of Fairborn to the
southwest. Surface water drainage is monitored at several National Pollutant Discharge Elimination
System stations located along the Mad River. The storm drain network and Hebble Creek are potential
pathways for the transport and migration of environmental contaminants in OU 2.
2.1.2.4 Hydrogeology
The groundwater and unconsolidated deposits that underlie the POL Storage Area vicinity spill sites form a
part of the Miami Buried Valley Aquifer System, which was designated as a sole source aquifer in 1988
under Section 1424(e) of the Safe Drinking Water Act of 1974 and succeeding amendments. Depth to the
water table in this aquifer is typically 5 to 15 ft below ground surface.
Groundwater flow in these deposits is from areas of recharge to areas of discharge and is generally
westward from the city of Fairborn and OU 2, through WPAFB, and toward the Mad River. Recharge
typically occurs in the relatively higher areas away from the Mad River, and discharge occurs in the
topographically low area of the Mad River.
Water supply wells for Fairborn and WPAFB are additional (potential) discharge points for groundwater.
However, the hydraulic conductivity, hydraulic gradients, and recharge rate indicate the Fairborn North and
West Park well fields and the WPAFB wells are not likely to receive contaminants migrating in
groundwater from the POL Area because the POL Area is not in the capture zones for these wells.
A more detailed explanation of the geology and hydrogeology at Spill Sites 2,3, and 10 may be found in
the Final Remedial Investigation Report for Operable Unit 2, Wright-Patterson Air Force Base.
2.1.3 Ecology
The ecological survey focused on characterizing the ecological communities and nondomesticated plant
and animal species in a 1 -mile radius of the OU 2 sites. Remnant hardwood forest makes up 5% of the
study area and provides habitat to white-tailed deer, eastern cottontail rabbit, eastern gray squirrel, blue
jay, and mourning dove. Ruderal communities make up 47% of the study area and include the grassy
areas of OU 2, residential housing, commercial and industrial areas in Fairborn, part of the golf course on
WPAFB, and other developed areas of WPAFB. The native species are much the same as the forest areas.
Open grassy areas or meadows comprise about 24% of the study area. These areas consist of grasses,
forbs, and some shrubs, where the commonly observed fauna include birds and small mammals. Prime
farmland makes up 6% of the study area and has much the same fauna as the forest areas. A gravel mine
comprises 5% of the area with limited isolated shrubs and grassy areas. Aquatic and wetland
WPAFB Draft Record of Decision for Spill Sites 2,3 and 10
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communities consist of Hebble Creek, Medway Lake, Bass Lake, several gravel pits, and adjacent riparian
wetlands and comprise less than 2% of the study area. Vegetation consists of box elder, cottonwood, and
various sedges and grasses; the fauna include various species of aquatic arthropods and fish. The
remaining 11% of the area is WPAFB runways, taxi ways, and aircraft parking areas.
No federally listed or proposed threatened or endangered species are known to live within the study area.
However, two federal candidate species—the eastern massasauga rattlesnake and the glade mallow—have
been reported outside the 1-mile zone at WPAFB. The upland sandpiper, a state-listed threatened species,
is known to nest in the grassy areas near Spill Site 10.
2.1.4 Demography and Land Use
The Base is the Headquarters to the Air Force Materiel Command and home to organizations such as the
Air Force Wright Aeronautical Laboratories, Air Force Institute of Technology, and the Aeronautical
Systems Center. The Base has a significant proportion of its acreage devoted to logistical
support/warehouse land uses, research and development, and administrative and classroom space. Airfield
functions constitute 24% of the on-Base land uses. WPAFB is not scheduled for closure under the Base
Realignment and Closure program.
As of 1990, the city of Fairborn had a population of 31,298. The daily population at WPAFB can exceed
40,000 people and includes approximately 18,000 civilian personnel, 10,000 military personnel, and 10,000
contractor employees. Access to WPAFB is restricted to military personnel, civilian employees, and other
authorized persons. Access to the POL Storage Area vicinity is restricted to authorized personnel.
Military, industrial, commercial, office, residential, educational, agricultural, and recreational land use
exists within a 1 -mile zone of OU 2.
The OU 2 POL Storage Area sites are used to store heating oil, automotive fuels, and jet fuel products.
The POL Storage Area consists of a complex of large aboveground storage tanks ranging in capacity from
15,000 gal to 840,000 gal with a total storage capacity of 38,000,000 gal. These tanks are located in a
bermed area lined with geotextile material. Petroleum products are transferred within the POL Area
through a network of recently installed aboveground piping. Some underground piping remains in service
for distribution to outlying areas.
22 SITE HISTORY AND ENFORCEMENT
12.1 Site History
Historically, the OU 2 POL Storage Area was used to store heating, automotive, and jet fuel products. The
petroleum products were transferred to fueling stations or other areas of the Base through a network of
underground pipes and valves. The underground piping was abandoned in place and replaced with
aboveground piping in 1996.
Spill Site 2 is associated with the release of approximately 8,300 gal of JP-4 jet fuel from Tank 256 in
April 1976. The spill occurred within a diked area surrounding the tank. The wells hi both the North Well
Field and the West Park Well Field were on reserve status at that time.
Spill Site 3 involved the release of 1,200 to 2,500 gal of No. 2 fuel oil from Tank 272 in March 1981. The
spill occurred between Tank 272 and the fueling station.
The spill at Site 10 occurred in October 1989 when a flange gasket ruptured on a JP-4 hydrant and released
an estimated 150 gal of fuel. This site is surfaced with limestone gravel and asphalt; at the time of the fuel
spill, the site was grass covered.
WPAFB Draft Record of Decision for Spill Sites 2, 3 and 10 8
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While these are the documented spills in the POL Storage Area, the underground piping system may have
had other leaks and breaches of integrity that also have contributed to the contamination in the soil and
groundwater in the area.
Spill cleanups were conducted at the time of the spills at Spill Sites 2,3, and 10. These actions were taken
at the initiative of the WPAFB. At Spill Site 2, three recovery wells were installed adjacent to Tank 256
and approximately 4,800 gal of spilled jet fuel was recovered. At Spill Site 3, a recovery trench was dug
adjacent to the spill but no fuel oil was recovered At Spill Site 10, absorbent materials were used to
recover about 10% of the spilled jet fuel.
A removal action began in March 1991 in the POL Storage Area vicinity. This removal action consisted of
installing two piezometers to investigate the nature of contamination in the POL Storage Area vicinity,
installing a skimmer pump in Monitoring Well 04-518-M, and providing a 1,000-gal aboveground tank to
hold fuel recovered from the well. Approximately 1,600 gal of petroleum product were recovered through
April 1995 as a result of this removal action.
A second recovery well system including an oil/water separator, a product storage tank, an equalization
tank, an air stripper, vapor-phase carbon filters, and a water-filtration unit began operation in May 1993.
About 82 gal of free product had been recovered through March 1995. The aboveground treatment system
for this recovery well was destroyed by fire in November 1995. Because results of the RI indicate no
appreciable free product exists in this area and only minimal amounts were collected during 18 months of
operation, there are no plans to rebuild this system.
A third removal action began in September 1993 with the addition of a passive recovery system in
Monitoring Well WP-NEA-MW21-3S. Approximately 5 gal of free product has been removed by this
system.
A bioventing application evaluation study was initiated in March 1993 to address petroleum hydrocarbons
contaminating the soil in the POL Storage Area vicinity. The study included measuring the unsaturated
soil system's ability to naturally degrade petroleum hydrocarbons. Air was forced into the subsurface soil
to enhance natural degradation activity. Based on this study, a pilot bioventing system was installed and
operated from June 1993 to May 1994 to demonstrate the viability of soil bioventing at OU 2.
WPAFB initiated upgrades to the POL facility during March 1994 by installing fixed roofs and new valves
on the tanks and installing an oil/water separator. In 1996 new geotextile linings were added to the
secondary containment areas around the storage tanks and underground fuel lines in the POL Storage Area
vicinity were flushed, abandoned hi place, and replaced with aboveground lines.
223 Enforcement
hi February 1988, WPAFB entered into an Administrative Order of Consent with OEPA that specified
requirements for conducting investigations and implementing cleanup actions pursuant to Ohio Revised
Code Chapters 3734 and 6111. WPAFB was placed on the USEPATs NPL in October 1989. Subsequently,
in March 1991, WPAFB signed a Federal Facilities Agreement (FFA) with USEPA, Region V. General
purposes of the FFA include ensuring environmental impacts associated with past and present activities at
WPAFB Draft Record of Decision for Spill Sites 2,3 and 10
-------
the site are thoroughly investigated and appropriate response actions are taken to protect public health,
welfare, and environment.
23 HIGHLIGHTS OF COMMUNITY PARTICIPATION
WPAFB currently has an Environmental Advisory Board that consists of representatives from local
government agencies, businesses, and the community groups playing an active role in the Installation
Restoration Program (ERP)Aprocess. The board meets quarterly to discuss and concur on a variety of topics
regarding the environmental program at WPAFB. The board has the opportunity to review and comment
on all documents addressing the IRP sites. WPAFB offered opportunities for public input and community
participation during the RI and Proposed Plan for Spill Sites 2,3, and 10 at OU 2. The Proposed Plan was
made available to the public in the Administrative Record and the Information Repository. The notice of
availability for the Proposed Plan was published in the Dayton Daily News (local paper) on Sunday,
February 23,1997, and in The Skywriter (Base newspaper) on February 28,1997. A public comment
period was held from February 24 through March 25,1997.
The public comment period was not extended as there were no requests for an extension. The Base held a
public meeting on March 4,1997, at 6:00 pjn to discuss the investigatory activities that took place at the
Spill Sites. Representatives from the USEPA, OEPA, and WPAFB were all present to answer questions
about the Base, the OU 2 POL Storage Area vicinity sites, and the recommended alternative. No members
of the public attended the meeting and no written comments were received. These community participation
activities fulfill the requirements of Section 113(k)(2XB)(i-v) and 117(a)(2) of CERCLA.
2.4 SCOPE AND ROLE OF SPILL SITES 2,3, and 10
This ROD documents the selected remedy for subsurface soil and groundwater contamination at Spill Sites
2,3, and 10, which are part of OU 2. OU 2 represents one component of a comprehensive environmental
investigation and cleanup presently being performed under the Installation Restoration Program (IRP) at
WPAFB. The IRP has divided the Base into 11 OUs, each with several IRP sites located in close proximity
to each other. In most cases, the RIs conducted at the OUs addressed only the source areas. Groundwater,
surface water, and sediment flowing from these areas will be monitored and addressed under the Basewide
Monitoring Program.
Remedial actions for several IRP sites are being addressed hi a streamlined method with presumptive
remedies. (Presumptive remedies are those approved by the USEPA as proven remedies for CERCLA sites
with similar contaminants.) Sites remediated under this streamlined process forego the standard FS process
and can proceed into remedial action.
Three RODs have been issued as a result of the RIs at WPAFB. These are the "On-Source" and
"Off-Source" RODs for OU 1 and the No Action ROD for soil at 21 IRP sites. The No Action ROD
addresses soil at sites across WPAFB, including 5 sites from OU 2: the Coal and Chemical Storage Area,
Temporary Coal Storage Pile, Long-Term Coal Storage Area, Burial Site 1, and the Building 89 Coal
Storage Pile.
2.5 SUMMARY OF SITE CHARACTERISTICS
Contaminants found at Spill Sites 2,3, and 10 in the POL Storage Area vicinity are those generally
associated with petroleum storage areas; namely, benzene, toluene, ethylbenzene, and xylenes (BTEX),
semivolalile organic compounds (SVOCs) called polycyclic aromatic hydrocarbons (PAHs), and some
WPAFB Draft Record of Decision for Spill Sites 2,3 and 10 10
-------
metals. While the spills at Spill Sites 2,3, and 10 are the documented sources of contaminants in this area,
the underground piping system may have had leaks and breaches of integrity that also have contributed to
contamination in the soil and groundwater in the area. Following is a summary of investigation results in
the POL Storage Area vicinity. A detailed discussion of the types and behaviors of the chemicals at Spill
Site 2,3, and 10 is presented in the OU 2 RI Report.
The potential migration pathways for contaminants at OU 2 include leaching into the groundwater,
groundwater migration, and volatilization and migration into air.
25.1 Summary of Site Soil Characteristics
Volatile organic compound (VOC) soil contamination is dominated by BTEX compounds. During the RI,
observed concentrations of BTEX in subsurface soil averaged 4.9 milligrams per kilogram (mg/kg) for
benzene, 22.6 mg/kg for toluene, 22.2 mg/kg for ethylbenzene, and 30.7 mg/kg for xylenes. The greatest
contamination is in the subsurface soil at or near the water table, beneath and immediately west of the POL
Storage Area (Fig. 3). It is important to note that Fig. 3 is based on data gathered during the RI and that no
benzene, toluene, or ethylbenzene was detected in supplemental subsurface soil samples collected in May
1997. Xylenes were detected in one sample at S.3 ug/kg. Additionally, no benzene was detected in soil gas
samples collected during the May 1997 sampling event SVOC contamination is dominated by PAHs, with
the greatest number and highest concentrations found at and southwest of the POL Storage Area vicinity.
PAHs generally are not very mobile. Soil contamination by inorganics is limited to metals. The only metal
to exceed its risk-based comparison concentration was beryllium.
The persistence of BTEX adsorbed onto soil is dependent primarily on biodegradation. Based on their
physical characteristics such as low molecular weight, high degree of solubility, vapor pressure, etc.,
BTEX can be expected to be moderately to highly mobile in the environment and exhibit the ability to
volatilize to the atmosphere and leach into the groundwater or be carried in runoff to surface waters. These
characteristics that give BTEX their mobility also help to enhance their degradability. The distribution of
petroleum hydrocarbons at the site suggests petroleum hydrocarbons have migrated into the groundwater
from the soil.
2.5.2 Summary of Site Groundwater Characteristics
The investigations delineated a dissolved petroleum hydrocarbon plume dominated by BTEX compounds
originating from the POL Storage Area and extending west along the path of groundwater flow.
Investigations at OU 2 and surrounding areas determined that groundwater was moving west in the vicinity
of OU 2 and it eventually discharges into the Mad River. Based on direct measurement of aquifer
properties, it may take anywhere from 19 to 38 years for groundwater to reach the Mad River from the
vicinity of the POL Storage Area.
The principal BTEX compound detected in groundwater was benzene, which occurred at concentrations in
excess of the maximum contaminant level (MCL) of 5 micrograms per liter (ug/L)- During the RI,
observed concentration of benzene in groundwater averaged 73 ng/L. Other groundwater contamination
included trichlorethene (TCE), PAHs, and some metals. TCE and six PAHs were detected at levels
WPAFB Draft Record of Decision for Spill Sites 2,3 and 10 11
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greater than the MCLs at one well location (WP-NEA-MW26-3S), approximately 1,200 ft downgradient of
the POL Storage Area vicinity and near the east side of Building 143 (Fig. 4). Groundwater contamination
by metals showed a direct relationship with the fuels-related contamination. Hie wells and samples with
benzene concentrations exceeding the MCL also had elevated iron, manganese, and arsenic concentrations.
Again, it is important to note that Fig. 4 is based on data gathered during the RI and that levels of BTEX
compounds have significantly decreased based on supplemental groundwater sampling conducted in May
1997. Additionally, levels of dissolved oxygen, nitrate, sulfate, and ferrous iron measured during the May
1992 sampling event support the finding that natural attenuation is occurring effectively.
Leaching of BTEX compounds from subsurface vadose zone soil was probably the principal contaminant
source, and transport of these contaminants is the principal migration pathway. The dissolved petroleum
hydrocarbon plume is not expected to increase in overall size because the contaminant levels are decreasing
and the size is close to its theoretically calculated size based on the site characteristics. The shape of the
dissolved petroleum hydrocarbon plume and analytical data indicate natural processes are acting to
effectively limit the migration of BTEX contaminants in the groundwater. In addition, the site data suggest
the groundwater has enough assimilative capacity to degrade the hydrocarbons currently in the aquifer.
The degree of degradation will be dependent on the mixing of the dissolved plume with the oxidizing
shallow groundwater. Dissolved oxygen appears to be a key ingredient in the plume
degradation/containment.
Using a concentration of 100 jig/L total volatile hydrocarbon (TVH), the volume of contaminated
groundwater represented by the petroleum hydrocarbon plume is approximately 83.25 million gallons
containing approximately 16.2 gal of petroleum hydrocarbons (Fig. 4). This volume does not include free
product and does not indicate the total volume of the spills.
2.6 SITE RISKS
WPAFB conducted a baseline human health and ecological risk assessment as part of the RI to estimate the
probability and magnitude of potential adverse human health effects and environmental effects from
contaminants at the site.
2.6.1 Human Health Risk
The USEPA-approved human health risk assessment method followed a four-step process: (1) contaminant
identification, which identified those hazardous substances of significant concern at the site; (2) exposure
assessment, which identified actual or potential exposure pathways, characterized the receptor population,
and determined the extent of possible exposure; (3) toxicity assessment, which considered the types and
magnitude of adverse human health effects associated with the contaminants; and (4) risk characterization,
which summarized the potential risks posed by the site contaminants.
2.6.1.1 Contaminant Identification
All detected contaminants in the POL Storage Area vicinity were selected for analysis in the risk
assessment Not all the detected contaminants can be evaluated because of the lack of toxicity
information.
WPAFB Draft Record of Decision for Spill Sites 2.3 and 10 13
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2.6.12 Exposure Assessment
The OU 2 sites were grouped into exposure units by environmental media (such as soil and groundwater)
based on the likelihood of people, plants, and animals coming in contact with these media. The exposure
unit for the sites in the POL Storage Area vicinity included Spill Sites 2,3, and 10; the Coal and Chemical
Storage Area; and the Temporary Coal Storage Pile. The majority of the risk from the sites in the POL
Storage Area vicinity is contributed by the spill sites, from BTEX contamination, and the PAHs.
The objective of the exposure assessment is to estimate the type and magnitude of potential exposures to
chemicals that may be present at, or migrating from, the sites. Exposure scenarios representative of the
current and future potential exposures were developed. These scenarios included a commercial/
industrial worker exposed to ingestion and dermal absorption of surface soils and also exposed to outdoor
air; a future commercial industrial worker exposed to the surface soil and the groundwater from the site;
and a future construction worker was assumed to labor in the subsurface soil (0-12 ft deep) and to use
groundwater from the site for a period of 1 year. An off-site resident was assumed to use groundwater
pumped from the POL Storage Area vicinity. This assessment addressed the possibility of the installation
of production wells in the vicinity of Spill Sites 2,3, and 10. The groundwater exposures in these
scenarios are hypothetical, i.e., situations that do not currently exist and are not likely to exist in the future.
The exact assumptions and methods of quantifying exposure in these scenarios are given in Sect. 6.3 of the
RI.
The exposure assessment uses an exposure point concentration. Exposure point concentrations are
concentrations of a chemical in a given medium that a receptor may be exposed to at a specific location.
Two exposure point concentration estimates were used in the baseline risk assessment: a reasonable
maximum exposure (RME) and an average central tendency (CT) exposure. The RME is the highest
exposure that could reasonably be expected for a given pathway at a site and is intended to account for both
uncertainty in the contaminant concentration and variability in the exposure parameters. The CT exposure
is the expected average exposure and is evaluated for comparison purposes only. The exposure point
concentrations were determined after a statistical evaluation of the valid data for a site. For the
contaminant plume in groundwater under the POL vicinity, the four wells in the center of the plume were
used to determine exposure point concentration following USEPA guidance. The wells containing free
petroleum product are not an accurate representation of realistic exposure to potable water and were not
included in the risk assessment. For a detailed discussion of the statistical treatment of the data in
determining the exposure point concentration, please see Sect 6.3 of the RI.
2.6.1.3 Toxitity Assessment
Human health risks or hazards are defined for two classes of chemical contaminants: carcinogens and
noncarcinogens. Exposure to carcinogenic chemicals may result in an increased risk of a specific type of
cancer. The risk of cancer in a population is expressed as the chance of the occurrence of that type of
cancer per numbers of the population. These cancers are over and above the background rate of cancer in
the United States; that is, they represent an excess cancer risk. A risk level of one in a million (1 x 10"*)
means that one additional person out of 1 million people could develop cancer as a result of exposure to the
environmental contaminant. USEPA has established that an excess cancer rate of one in a million people
to one in ten thousand (1 x 10"6 to 1 x 10"4) people is the target risk range for determining the effectiveness
and health protectiveness of an environmental remedial action. Cancer risks greater than one in ten
thousand generally require evaluation of remedial actions to reduce the risks to the population.
WPAFB Draft Record of Decision for Spill Sites 2,3 and 10 15
-------
Cancer risk is calculated using a USEPA-derived value called the cancer slope factor. The cancer slope
factors for the OU 2 RI were obtained from the USEPA Integrated Risk Information System (IRIS) if
possible. If values were not available from IRIS, the USEPA Health Effects Assessment Summary Tables
(HEAST) were used.
For noncarcinogenic contaminants, the likelihood of adverse health effects is expressed as a numerical ratio
called the Hazard Quotient (HQ). Values for the HQ of greater than 1.0 indicate that noncarcinogenic
adverse health effects may be likely to occur. The likelihood of noncarcinogenic adverse health effects is
evaluated using the reference dose (RfD) or the reference concentration (RfC) for inhalation exposure. The
RfDs and RfCs used in the RI were obtained from USEPA IRIS and HEAST data sources.
The toxicity values for carcinogenic and noncarcinogenic exposure are derived for oral or inhalation
exposures. In some cases it was appropriate to modify an oral RfD or slope factor to account for dermal
exposure to a hazardous chemical. The methodology and justification for this modification is given in
Sect. 6.4 of the RI.
For the PAHs, USEPA relative potency factors were used to adjust the slope factors for all carcinogenic
PAHs based on the slope factor of benzo(a)pyrene. The relative potency factor for benzo(a)pvrene is given
as 1.0; for benzo(a)anthracene, 0.145; and dibenzo(aji)anthracene, 1.11. Please see the RI for a complete
discussion of the PAH toxicity values.
2.6.1.4 Risk Characterization
Presented in Table 1 is the cumulative risk for the exposure pathways chosen for the sites in the POL
Storage Area vicinity. Arsenic, beryllium, and benzene are the primary contributors to carcinogenic risk
for all groundwater exposures. The primary carcinogens in surface soil and subsurface soil are the PAHs
[benzo(a)pyrene, dibenz(aji)anthracene, benzo(a)anthracene], and beryllium.
The primary contributing contaminants to noncarcinogenic risk include the metals manganese, antimony,
and arsenic. In surface soil and subsurface soil, the metals manganese, cadmium, antimony, and vanadium
contribute to the noncarcinogenic risk.
Risks for the commercial industrial worker exposure to surface soil and groundwater and the hypothetical
residential exposure to groundwater exceed the target value of one in ten thousand excess cancers using the
RME assumptions. Noncarcinogenic HQs for the metals exceed the EPA target of 1.0 for all scenarios
using the RME assumptions.
EPA guidance states that the one in ten thousand cancer risk level is not a finite line for the evaluation of
the need for remedial action. The project managers—in cooperation with the USEPA, OEPA, and the
public—may evaluate the need for specific actions at specific sites with risks slightly greater than the target
risk range. Worker risks were evaluated assuming no protective clothing.No members of the public are
currently exposed to the groundwater contamination from the POL Area vicinity. No production wells exist
in the contaminant plume and none are scheduled for construction. Therefore, it is unlikely that members
of the public or workers will exhibit adverse health effects from this site under realistic exposures.
WPAFB Draft Record of Decision for Spill Sites 2,3 and 10 16
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Table I. Human Health Risk Summary at the POL Storage Area Vicinity Sites
Receptor
Media
Primary Contaminant
Carcinogenic* Risk-
RME1
Cumulative
Primary
Contaminant
Carcinogenic
Risk-Cr
Cumulative
Primary
Contaminant
Non-Carcinogenic**
Risk-RME
Cumulative
Primary
Contaminant
Non-Carcinogenic
Risk-CT
Cumulative
Commercial Industrial Workers
Surface Soil
Benzo(a)pyrene
3xl
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2.6.2 Ecological Risk
An Ecological Risk Assessment (ERA) was performed for OU 2 and a 1-mile zone surrounding OU 2. The
contaminants evaluated in the ERA were from a large area, and it is difficult to isolate the effects of the
spill sites on the ecology of the area. The POL Storage Area is highly industrialized and is not a suitable
area for plant or animal species other than groundhogs or rodents. Metals, PAHs, and pesticides were
identified to possibly contribute to the detriment of the plant and animal species in the OU 2 area. The
uncertainties associated with the ERA and the conservative safety factors used resulted in the conclusion
that no significant ecological harm is likely to occur as a result of contaminants at OU 2.
2.7 IDENTIFICATION OF CONTAMINANTS NEEDING REMEDIATION
Using the RI and its Baseline Risk Assessment as a starting point, analytes detected during the
investigation were screened to identify those requiring remediation. Figure 5 illustrates the order in which
exposure point concentrations, or maximum observed concentrations for analytes, were compared to a
series of criteria to determine whether they represent a hazard to be remediated. The results of the
screening process indicate benzene in groundwater and BTEX in subsurface soil at Spill Sites 2, 3, and 10
in the POL Storage Area vicinity require remediation. PAHs were considered to not need specific remedial
actions because of the low CT risk and their presence hi general urban pollution. The metals were not
specifically addressed because the incidence of high levels of the metals was very sporadic and not
reproducible in the rounds of sampling. Other analytes, particularly arsenic in groundwater, probably are
elevated as a result of changes in redox conditions or the availability of complexing agents occurring as a
result of fuel contamination. These analytes would be diminished in concentration if the subsurface soil
source of the benzene is reduced.
The goal of the remedial action for subsurface soil is to reduce the BTEX contamination to levels below
the criteria set by the State of Ohio's Bureau of Underground Storage Tank Regulations (BUSTR). These
levels are : benzene, 0.17 milligrams per kilogram (mg/kg); toluene, 7 mg/kg; ethylbenzene, 10 mg/kg; and
xylene, 47 mg/kg. The goal of the remedial action for groundwater is to reduce the benzene contamination
to below the MCL of 5 //g/L, as specified in the Safe Drinking Water Act
2.8 DESCRIPTION OF ALTERNATIVES
This section presents narrative summaries of alternatives considered (following initial screening) for
remediation of benzene in groundwater and BTEX in subsurface soil at Spill Sites 2,3, and 10. These
alternatives represent a range of remedial options including no action, limited treatment actions, and
aggressive treatment actions. The development of the alternatives followed the expectations of USEPA for
remediation of CERCLA sites.
Table 2 provides a summary of the process options associated with each alternative developed for detailed
analysis. Descriptions of the eight alternatives include estimates of the construction cost, the annual
operation and maintenance (O&M) cost, present worth value (i.e., what it would cost today to build and
operate into the future), and remediation times. Estimated remediation times do not include monitoring,
which will continue for 11 years for all alternatives.
Table 3 provides a summary of the primary applicable or relevant and appropriate requirements (ARARs)
for all alternatives evlauated.
WPAFB Draft Record of Decision for Spill Sites 2.3 and 10 18
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EittbfahSiwChemiat-Spcdfic
Remedial Action Ob|Bctives
Develop General Response Actions
Describing Ann or Volumes of Media
to Which Containment, Treatment, or
Removal May Be Appfed
Identify Potential Treatment md
Disposal Technologies and Screen
Based on Technical bnplementabiity
1
Evaluate Process Options Based on
Effectiveness, Imp(ememabi6ty,znd
Relative Cost, to Select a Representative
Process for Each Technology Type
Yes
CM
p
Technoloojes into
Atometives
Repeat Previous Scoping Steps:
- Detenrine New Data Needs
• Develop Sempfing Stntegtes
and Anslvtical Support to
Acquire Additional Data
-Repeat Steps in Rl She
Characterization
Individual Analyses
of Ahenutives Against
Evaluation Criteria
Comparative Analysis
of Alternatives Against
Evaluation Criteria
Issue FS
Report
Source: USEPA, 1988.
LEGEND
DATE: 01-28-97
FILENAME: FSSC1-01.DGN
Fig. 5. Overview of the Feasibility Study Process.
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Table 2. Summary of Remedial Alternatives
Alternative
Process option GW1 GW2A GW2B GW2C GW3C GW4C GWSC GW6
In situ Biodegradation of subsurface XX X
soil
Natural Attenuation of Ground water X X X X
O&M of Product Removal Systems XXX X XXX
Institutional Controls XX X X XXX
Subsurface Soil and Groundwater XXX X XXX
Monitoring
Subsurface Soil Bioventing X X
Bioslurper Wells/Soil Vapor X
Extraction
Groundwater collection and XXX
treatment using metals
precipitation and chemical
oxidation with surface
waterdischarge
Groundwater air sparging X
Subsurface soil vapor extraction X X
2.8.1 Alternative GW1
Alternative GW1, the No Action alternative, is considered in the range of alternatives to serve as a baseline
or to address sites that do not require active remediation. NCR and CERCLA guidance require that the No
Action alternative be evaluated. This alternative assumes that no remedial action will occur and that the
site would be left in its present condition. The existing recovery actions would be dismantled. Any
changes to the site conditions would be a direct result of natural processes and no monitoring would be
conducted to document changes in contaminant levels. Minimal cost is associated with this alternative.
2.8.2 Alternative GW2A
Alternative GW2A uses natural processes, institutional controls, and monitoring to address contamination
of groundwater and subsurface soil. Components of this alternative are:
• in situ biodegradation of subsurface soil,
• natural attenuation of groundwater,
• O&M of existing removal actions,
• institutional controls, and
• subsurface soil and groundwater monitoring.
In situ biodegradation of subsurface soil and natural attenuation of groundwater depend on natural
processes to remediate contamination. Indigenous microbial communities use organic materials as food or
as a catalyst in their metabolism thereby degrading organic contaminants to innocuous compounds like
carbon dioxide and water. These natural processes have been demonstrated to be a permanent, effective,
environmentally sound resolution to petroleum contamination.
WPAFB Draft Record of Decision for Spill Sites 2,3 and 10 20
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Table 3. Summary of Applicable or Relevant and Appropriate Requirements
ARARs Citation
Requirement
Alternative and Rationale
Safe Drinking Water Act
40CFR 141
Ohio Drinking Water Rules
OAC 3745-81,82
Set standards for protection of drinking
water sources.
GW1. GW2A. GW2C, GW3C. GW4C,
GWSC, GW6 - Used to develop clean-up
goals for all alternatives evaluated.
USEPA Clean Water Act
Ambient water quality criteria.
40 CFR 414 and 422
Establishes criteria and control
procedures for specific toxic
substances as well as total toxkity in
surface waters based on intended use.
GWSC. GW4C. and GWSC -
Effluent discharges from groundwater
treatment systems may impact Hebble
Creek.
Federal and Slate National Pollutant
Discharge Elimination System
(NPDES). including Ohio Water Quality
Standards
40 CFR 125, 122, and 414
OAC 3745
ORC6111
Provide standards for both on-site and
off-site discharges to surface water.
GW3C. GW4C. and GWSC -
Effluent discharges from groundwater
treatment systems may impact Hebble
Creek.
Ohio Bureau of Underground Storage
Tank Regulations (BUSTR)
OAC 1301:7-9-13
Establishes action levels for soil and
groundwater contaminated by benzene,
toluene, ethylbenzene, and xylene
(BTEX) and total petroleum
hydrocarbons.
GW1. GW2A, GW2C, GW3C, GW4C,
GWSC. GW6 - Used to develop
subsurface soil clean-up goals for all
alternatives evaluated.
Ohio Groundwater Treatment Systems
OAC 3475-31
Requires installation permit for hew
groundwater treatment systems and/or
a new process waste discharges to the
municipal sewer.
GW3C, GW4C, GWSC, and GW6 -
Groundwater treatment systems will
require a permit.
OAC 3745-9-19
Requires permit to inject or reinject
any substance into the groundwater.
GW2B and GW4C - Subsurface soil
bioventing may introduce air into the
groundwater.
GW6 - Air sparging will introduce air into
the groundwater.
RCRA Land Disposal Restrictions
40 CFR 261
RCRA Waste Storage greater than
90 days
40 CFR 264
RCRA Waste Storage less than 90 days
40 CFR 265
Provides a framework for safe
handling and management of
treatment-derived waste materials.
GW2C, GWSC and GW6 - Disposal of
activated carbon used to clean soil vapor
extracted from subsurface soil.
GW3C, GW4C and GWSC - Disposal of
sludge generated by chemical precipitation
of metals in groundwater.
WPAFB Draft Record of Decision for Spill Sites 2.3 and 10
21
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Numerous factors such as soil moisture content, porosity, temperature, pH, oxygen, redox potential,
presence of suitable microbes, nutrients, and the types and concentrations of contaminants affect the
potential for, and rate of, biodegradation. Data collected during the RI, BioPlume II modeling performed
as part of the RI, and VLEACHSM modeling performed as part of the FS demonstrate that biodegradation
activities are occurring in the POL Storage Area vicinity. The measured absence and depressed levels of
dissolved oxygen (DO) concentrations in the contaminated groundwater is a good indicator that aerobic
(oxygen-sufficient) biodegradation is occurring. The depleted sulfate and nitrate and increased iron
concentrations observed are indicative of anaerobic (oxygen-deficient) biodegradation taking place in areas
where the dissolved oxygen has been depleted. Calculations performed during the RI estimate the aquifer
in the POL Storage Area is capable of assimilating at least 17,000 to 21,000 ug//L of petroleum
hydrocarbons, which is well above the highest BTEX and total volatile hydrocarbons concentrations
observed in the groundwater. In situ respiration tests performed as pan of the bioventing field initiative
verified that biodegradation is naturally occurring within the subsurface soils.
O&M of existing removal actions would continue. Institutional controls such as fences and deed
restrictions ensure access to the site is restricted and future land use is appropriate. Subsurface soil gas and
groundwater monitoring will evaluate the performance of in situ biodegradation and natural attenuation and
provide the data needed to verify the effectiveness of the alternative to meet remedial action objectives for
subsurface soils and groundwater. The effectiveness of the alternative will be evaluated under the
Basewide Monitoring Program (BMP). Monitoring will continue for 3 years after cleanup goals are
achieved.
The estimated remediation time for Alternative GW2A is 8 years using the combined results of
BIOPLUME H groundwater modeling performed during the RI and VLEACHSM modeling performed
during the FS. Results of these models indicate remediation goals for BTEX in subsurface soil will be
reached in 6 years and the remediation goal for benzene in groundwater will be reached within 2 years of
the removal of potential sources.
For costing purposes, a total of nine groundwater and subsurface soil gas monitoring wells were assumed to
be sampled twice a year for 11 years. Confirmatory soil sampling will verify remedial goals are reached.
The monitoring program will be developed and implemented under the BMP, which will determine the
actual number and location of samples, sampling frequency, and the list of analytes.
The primary components for capital costs are the periodic replacement of existing fences and warning
signs. The major components of the O&M cost are maintenance of existing fences and period subsurface
and groundwater monitoring. Cost estimates do not include the continued O&M of the existing recovery
actions because these costs are applicable across all alternatives (except No Action) and are being incurred
as pan of a separate removal action. Costs for Alternative GW2A are presented below:
Capital Cost $30,000
Annual O&M Cost $77,000
Present Worth Value $610,000
Estimated Remediation Time 8 years
2.8.3 Alternative GW2B
Alternative GW2B consists of the same components as Alternative GW2A except subsurface soil would be
actively remediated by soil bioventing. Components of this alternative are:
WPAFB Draft Record of Decision for Spill Sites 2,3 and 10 22
-------
soil bioveming,
natural attenuation of groundwater,
O&M of existing removal actions,
institutional controls, and
subsurface soil and groundwater monitoring.
Bioventing promotes volatilization and biodegradation of organic constituents in soil by pumping air into,
or removing soil gas from, a battery of shallow wells. Hie increased air flow increases the amount of
oxygen available for microbial degradation and enhances natural degradation processes. Bioventing is an
in situ process widely used to remediate fuel-spill sites, and its effectiveness for VOC destruction has been
proven.
The bioventing system would include air injection around the area with high VOCs in the vadose zone.
Using 100-ft well spacing based on a 50-ft radius of influence (determined by modeling), a total of 28 wells
would be installed (Fig. 6). Wells would not be installed between Spill Sites 2 and 3 to avoid breaching the
lined and bermed Tank Farm.
As in Alternative GW2A, groundwater would be remediated by natural processes, O&M of existing
removal actions would continue, institutional controls would restrict access to the site and ensure future
land use is appropriate, and subsurface soil gas and groundwater monitoring would be conducted under the
BMP to verify the effectiveness of the bioventing system and natural attenuation.
Based on the preliminary bioventing test results, from 3.4 to 11 mg/kg-day for a biodegradation rate, a
volume of 87,000 yd3 of contaminated subsurface soil, and a worst-case BTEX value of 410 mg/kg,
bioventing of these soils should take less than 1 year to reach remedial goals. As in Alternative GW2A,
benzene concentrations in groundwater would be lowered below the remediation goal of 5 ug/L through
natural attenuation within 2 years after removal of the vadose zone source contamination. Thus the total
estimated remediation time is 3 years.
For costing purposes, a total of nine groundwater and subsurface soil gas monitoring wells were assumed to
be sampled twice a year. Because the Tank Farm is considered inaccessible to all active remedial
technology options, the monitoring program will continue for 11 years, as described in Alternative GW2A.
The primary components for capital costs are the periodic repair and replacement of fences and signs and
the installation of the bioventing system. The major O&M cost components are maintenance of the
bioventing system and the periodic monitoring/sampling program. Cost estimates do not include the
continued operation and maintenance of the existing recovery actions because these costs are applicable
across all alternatives (except No Action) and are being incurred as part of a separate removal action.
Costs for Alternative GW2B are presented below:
Capital Cost $870,000
Annual O&M Cost $140,000
Present Worth Value $1,600,000
Estimated Remediation Time 3 years
WPAFB Draft Record of Decision for Spill Sites 2,3 and 10 23
-------
x' / .''// .-!^~
Nest Pork
Well Field
400 800
iE
SCALE IN FEET
LEGEND
IOM bouidor}.
Looatlcnof »IH lltM.
lln* to*
rrepOMd loeatlen far toll
blovmtlng / blMlurptr
/ vapor Mtractlon wl I
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boNd an a M foot
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oonomb'otlon oontoiif.
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•oil of tt» MNT toklt. In
uo/kg. Intcnnl It vorlobl*..
DMhtd rfwrt inftrrM.
SCALE: 1*= 400' - 0"
DATE: 06-03-97
IIFNAUF:
Fig. 6. Conceptual Plan for Soil Bioventing/Bioslurper/Vapor Extraction Wells.
-------
2.8.4 Alternative GW2C
Alternative GW2C is similar to alternative GW2B except treatment of subsurface soil would be
accomplished by bioslurper wells/soil vapor extraction instead of bioventing. Components of this
alternative are:
• bioslurper wells/soil vapor extraction,
• natural attenuation of groundwater,
• O&M of existing removal actions,
• institutional controls, and
• subsurface soil and groundwater monitoring.
Treatment of subsurface soil would be accomplished by bioslurper wells/soil vapor extraction.
Volatilization and biodegradation of organic constituents in soil would be enhanced by removing VOCs
from subsurface soil using bioslurper wells and a central vacuum system. Extracted soil vapors would be
cleaned with vapor-phase carbon canisters. These same wells and vacuum system could also be used to
recover any free product flushed from subsurface soils. The bioslurper well configuration would be exactly
the same as in GW2B (Fig. 6). The overall effectiveness of Alternative GW2C should provide an
equivalent or shorter time for subsurface soil remediation than Alternative GW2B. In addition, this
alternative would provide a means to remove any free product flushed from subsurface soils.
As in Alternative GW2A, groundwater would be remediated by natural processes, O&M of existing
removal actions would continue, institutional controls would restrict access to the site and ensure future
land use is appropriate, and subsurface soil gas and groundwater monitoring would be conducted under the
BMP to verify the effectiveness of the bioventing system and natural attenuation.
The estimated remediation time is 3 years. Remediation of soils should take less than 1 year and, as in
Alternative GW2A, groundwater contamination would be lowered below remediation goals through natural
attenuation within 2 years after removal of the vadose zone source contamination.
For costing purposes, a total of nine groundwater and subsurface soil gas monitoring wells were assumed to
be sampled twice a year. Because the Tank Farm is considered inaccessible to all active remedial
technology options, the monitoring program will continue for 11 years, as described in Alternative GW2A.
The primary components for capital costs are the periodic repair and replacement of fences and signs and
the installation of the bioslurper/soil vapor extraction wells and treatment system. The major O&M cost
components are maintenance of the bioslurper wells and treatment system, replacement of the activated
carbon, and the periodic monitoring/sampling program. Cost estimates do not include the continued O&M
of the existing recovery actions because these costs are applicable across all alternatives (except No
Action) and are being incurred as part of a separate removal action. Costs for Alternative GW2C are
presented below:
Capital Cost $1,600,000
Annual O&M Cost $420,000
Present Worth Value $3,100,000
Estimated Remediation Time 3 years
WPAFB Draft Record of Decision for Spill Sites 2.3 and 10 25
-------
2.8.5 Alternative GW3C
Alternative GW3C provides for recovery and treatment of contaminated groundwater and in situ
biodegradation of subsurface soil. Components of this alternative are:
• in situ biodegradation of subsurface soil,
• groundwater collection and treatment using metals precipitation and chemical oxidation with surface
water discharge,
• O&M of existing removal actions,
• institutional controls, and
• subsurface soil and groundwater monitoring.
As in Alternative GW2A, subsurface soil would be remediated using natural processes. Groundwater
would be collected using a system of extraction wells and treated above ground by a metals removal
process followed by chemical oxidation. Extraction wells can effectively remove contaminated
groundwater for aboveground treatment. Precipitation can effectively remove inorganic constituents from
groundwater, which will eliminate probable iron and scaling problems. Chemical oxidation provides for
effective, permanent destruction of organic contaminants.
The groundwater recovery and treatment system severely damaged by fire in November 1995 would be
rebuilt and used as pan of this system. The components of this recovery system included a submersible
pump, a skimmer pump, and associated valves and piping. Three additional groundwater extraction wells
would be installed to collect contaminated groundwater: two within the nigh-VOC area and one
downgradient of the plume (Fig. 7). Placing extraction wells in the high-contamination area would
accelerate the extraction and subsequent remediation of groundwater. Based on groundwater modeling, the
best extraction rates estimated that a pumping rate of 75 gpm for the two wells in the high VOC area and
50 gpm for the downgradient well would create steady-state capture zones that would effectively capture
the contaminated groundwater plume.
The automated treatment system damaged by fire in 1995 was designed to run at a maximum flow rate of
150 gpm and included an oil/water separator, equalization tank, product storage tank, air stripper with
blower, filtration system, liquid-phase carbon adsorption filters, transfer pumps, and the associated valves
and piping. This system would be rebuilt and modified to include metal precipitation and chemical
oxidation processes. Metals would be precipitated through pH adjustment The sludge generated from the
metals removal process will need to be stored temporarily before transport and disposal at a RCRA-
permitted landfill.
The chemical oxidation system would use hydrogen peroxide in combination with ultraviolet light to
convert undesirable organic contaminants to simpler, nontoxic compounds of carbon, oxygen, and
hydrogen. Peroxide dosages were estimated to be 50 mg/L of groundwater treated, and power consumption
was estimated at 35 kW. Treated groundwater would be discharged to a nearby drainage system that
ultimately flows to the Mad River. The discharge would require a modification to the existing NPDES
permit from Ohio EPA.
O&M of existing removal actions would continue, institutional controls would restrict access to the site
and ensure future land use is appropriate, and subsurface soil gas and groundwater monitoring, as described
in GW2A, would be conducted to verify the effectiveness of in situ biodegradation and the groundwater
recovery and treatment system.
WPAFB Draft Record of Decision for Spill Sites 2,3 and 10 26
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Treatneny Syst
EMlrllng groMdwtor trwt-
Hot fopHltyHSOajM
M capacity).
nupoud loootlcn for
addltlanol gromtfntr
•
PrqwMdlooatlcnfar
^ow
point.
We»t Park
Well Field
EtflHtid ocpttr* zem In
~. tttraotlcn wtl vlolnlty.
SCALE IN FEET
PrcpoMd loaatlon fcr
(raiMntar ntraotlon wll
SncwTVHMmntrotlon In
loootlon of «>lll tltw.
trad art I trad tor* Mm
flroundntar of Hw Mtir
In ua/l. In
SCALE: 1*= 400' - 0"
DATE: 01-28-97
FIIFNAMF: FSSC3-05.DGN
.. , existing location of OH
""O fr* produot
ua/l. Intwol I* vortobU.
r« Infwrcd.
Fig. 7. Conceptual Plan Showing Location for Groundwater Collection and Treatment System.
-------
The estimated remediation time is 7 years. In situ biodegradation of contaminants in the subsurface soils
should take about 6 years, while modeling indicates extraction and treatment of groundwater would lower
benzene concentrations below the MCL within 1 year after removal of the vadose zone contaminant source.
For costing purposes, a total of nine groundwater and subsurface soil gas monitoring wells were assumed to
be sampled twice a year. Because the Tank Farm is considered inaccessible to all active remedial
technology options, the monitoring program will continue for 11 years, as described hi Alternative GW2A.
The primary components for capital costs are the periodic repair and replacement offences and signs,
installation of the extraction wells, and rebuilding and repairing the damaged groundwater treatment
system. The major O&M cost components are maintenance of the wells and treatment system, sludge
transport and disposal, hydrogen peroxide, pH-adjusting materials, and the periodic monitoring/sampling
program. Cost estimates do not include the continued operation and maintenance of the existing recovery
actions because these costs are applicable across all alternatives (except No Action) and are being incurred
as part of a separate removal action. Costs for Alternative GW3C are presented below:
Capital Cost $5,500,000
Annual O&M Cost $1,900,000
Present Worth Value $16,000,000
Estimated Remediation Time 7 years
2.8.6 Alternative GW4C
Alternative GW4C provides for active treatment of both subsurface soil and groundwater. Components of
the alternative are:
• subsurface soil bioventing,
• groundwater collection and treatment using metals precipitation and chemical oxidation with surface
water discharge,
• O&M of existing removal actions,
• institutional controls, and
• subsurface soil and groundwater monitoring.
Subsurface soil would be remediated with bioventing, as described in Alternative GW2B. Groundwater
would be collected using a system of extraction wells and treated above ground by a metals removal
process followed by chemical oxidation as described in Alternative GW3C. A conceptual layout for this
alternative is presented hi Fig. 8.
O&M of existing removal actions would continue, institutional controls would restrict access to the site
and ensure future land use is appropriate, and subsurface soil gas and groundwater monitoring, as described
in GW2A, would be conducted to verify the effectiveness of the remedy.
The estimated remediation time is 2 years. Remediation time for the subsurface soils would be less than 1
year, while extraction and treatment of groundwater would lower benzene concentrations in groundwater
below the federal MCL of 5 ug/L within about 1 year after removal of the vadose zone contamination
source.
WPAFB Draft Record of Decision for Spill Sites 2,3 and 10 28
-------
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-------
For costing purposes, a total of nine groundwater and subsurface soil gas monitoring wells were assumed to
be sampled twice a year. Because the Tank Farm is considered inaccessible to all active remedial
technology options, the monitoring program will continue for 11 years, as described in Alternative
GW2A.
The primary components for capital costs are the periodic repair and replacement of fences and signs,
installation of the extraction wells, and rebuilding and repairing the damaged groundwater treatment
system. The major O&M cost components are maintenance of the bioventing and groundwater extraction
wells, treatment system, sludge transport and disposal, hydrogen peroxide, pH-adjusting materials, and the
periodic monitoring/sampling program. Cost estimates do not include the continued operation and
maintenance of the existing recovery actions because these costs are applicable across all alternatives
(except No Action) and are being incurred as part of a separate removal action. Costs for Alternative
GW4C are presented below:
Capital Cost $6,300,000
Annual O&M Cost $2,000,000
Present Worth Value $10,000,000
Estimated Remediation Time 2 years
2.8.7 Alternative GW5C
This alternative is similar to Alternative GW3C and GW4C except subsurface soil remediation is
accomplished by soil vapor extraction rather than in situ biodegradation or bioventing. Components of this
alternative are:
• subsurface soil vapor extraction,
• groundwater collection and treatment using metals precipitation and chemical oxidation with surface
water discharge,
• operations and maintenance of existing removal actions
• institutional controls, and
• subsurface soil and groundwater monitoring.
Subsurface soil would be remediated by soil vapor extraction. As explained in Alternative GW3A, soil
vapor extraction promotes volatilization and biodegradation of organic constituents in soil by removing soil
gas from a battery of shallow wells. VOCs would be removed from the subsurface soil and processed
through a central vacuum system where the vapors would be cleaned with vapor-phase carbon canisters.
The extraction well configuration would be exactly the same as the soil bioventing wells described in
GW2B. Groundwater would be collected using a system of extraction wells and treated above ground by a
metals removal process followed by chemical oxidation as described in Alternative GW3C. A conceptual
layout for this alternative is presented in Fig. 8.
O&M of existing removal actions would continue, institutional controls would restrict access to the site
and ensure future land use is appropriate, and subsurface soil gas and groundwater monitoring, as described
in GW2A, would be conducted to verify the effectiveness of the remedy.
The estimated remediation time is 2 years. Remediation time for the subsurface soils would be less than 1
year, while extraction and treatment of groundwater would lower benzene concentrations below the MCL
within about 1 year after removal of the vadose zone contamination source.
WPAFB Draft Record of Decision for Spill Sites 2,3 and 10 30
-------
For costing purposes, a total of nine groundwater and subsurface soil gas monitoring wells were assumed to
be sampled twice a year. Because the Tank Farm is considered inaccessible to all active remedial
technology options, the monitoring program will continue for 11 years, as described in Alternative GW2A.
The primary components for capital costs are the periodic repair and replacement of fences and signs,
installation of the extraction wells, and rebuilding and repairing the damaged groundwater treatment
system. The major O&M cost components are maintenance of the soil vapor extraction and groundwater
extraction wells, treatment system, sludge transport and disposal, hydrogen peroxide, pH adjusting
materials, and the periodic monitoring/sampling program. Cost estimates do not include the continued
operation and maintenance of the existing recovery actions because these costs are applicable across all
alternatives (except No Action) and are being incurred as part of a separate removal action. Costs for
Alternative GWSC are presented below:
Capital Cost $7,000,000
Annual O&M Cost $2,100,000
Present Worth Value $11,000,000
Estimated Remediation Time 2 years
2.8.8 Alternative GW6
Alternative GW6 combines active, in situ technologies for subsurface soil and groundwater remediation.
Components of this alternative are:
• subsurface soil vapor extraction,
• groundwater air sparging,
• O&M of existing removal actions,
• institutional controls, and
• subsurface soil and groundwater monitoring.
As in Alternative GW5C, soil vapor extraction would be used to remediate subsurface soil. An
air-sparging system would be used to remediate contaminated groundwater in situ. Air sparging is a
process whereby clean air is introduced into the aquifer system. VOCs dissolved in the groundwater or
adsorbed to soil would be transferred to the sparged air and transported to the soil pores. A soil vapor
extraction system similar to that described in GW2B would capture the contaminated vapor for
aboveground treatment Air sparging and soil vapor extraction are proven in situ treatment processes and
are widely used to remediate rael-spill sites.
The air-sparging system would include air injection wells, a compressor, a blower, an air-water separator,
air emissions treatment, valves and piping, and instrumentation. The air-sparging and soil-vapor-extraction
integrated system consists of 30 nested wells. The integrated system would be configured similarly to
Alternative GW2B with the wells concentrated in the area with the highest VOCs (Fig. 9). Using 100-ft
well spacing based on a 50-ft radius of influence (determined by modeling), 28 wells would be installed in
the area. Two additional wells would be located downgradient of the plume. Wells would not be installed
between Spill Sites 2 and 3 to avoid breaching the lined and benrted Tank Farm.
An air-sparging flow rate has been assumed at 3 cfm, and the assumed extraction air flow rate is 100 cfm.
Under these assumptions approximately 6,000 g total volatile hydrocarbons will be removed from the
groundwater and extracted through the soil vapor extraction wells for aboveground treatment The
WPAFB Draft Record of Decision for Spill Sites 2,3 and 10 31
-------
8
1
ASV30
SPILL
Sift 10
.-'.
'// /Folrflald
••••--\ Pork
•» proporx ti ibelprt Comultanti. Baroh 1HT
::. -v\
j^ V\\
< \ ex. ^
WMt PorK
Nell Field
400
•?•
SCALE IN FEET
^
i.jw.
600
LEGEND
A5V01»
location of 9(11 iltti.
P ""1 t«n»tf and llmd »a* fora
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• ipdrolnfl orw vapor
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•laogra* p«r kllogro*
Inlvvai It wMbl».
IHMMB WOT (DIM KOM
or BH» •?*•»» M»mpoc>mioB.»
SCALE: 1*= 400' - 0*
DATE: 01-31-97
FILENAME; FSSC1-13.0CN
Fig. 9. Proposed Vapor Extraction and Air Spraging Wells.
-------
estimated rate of removal of total volatile hydrocarbons in the extracted air is approximately 2.1 g/L/min.
The materials and equipment needed to implement this alternative are available. The major factors to be
considered for implementation are well configuration, well spacing, radius of influence, air injection rates,
and process monitoring and operation requirements.
O&M of existing removal actions would continue to recover, and institutional controls would restrict
access to the site and ensure future land use is appropriate. Subsurface soil gas and groundwater
monitoring, as described in GW2A, would be conducted to determine optimum installation and operating
conditions and verify the effectiveness of the remedy.
The total estimated remediation time is 2 years. Remediation time for the subsurface soils would be less
than 1 year; remediation of the contaminated groundwater would be less than 1 year using air sparging.
For costing purposes, groundwater and soil gas monitoring wells were assumed to be sampled twice a year.
Because the Tank Farm is considered inaccessible to all active remedial technology options, the monitoring
program will continue for 11 years, as described in Alternative GW2A.
The primary components for capital costs are the periodic repair and replacement of fences and signs and
the installation of the air-sparging, soil-vapor-extraction, and vapor-phase treatment systems. The major
O&M cost components are maintenance of the air-sparging and soil-vapor-extraction systems, the vapor-
phase carbon air emissions treatment unit, and the periodic monitoring/sampling program. Cost estimates
do not include the continued O&M of the existing recovery actions because these costs are applicable
across all alternatives (except No Action) and are being incurred as part of a separate removal action.
Costs for Alternative GW6 are presented below:
Capital Cost $2,200,000
Annual O&M Cost $490,000
Present Worth Value $3,500,000
Estimated Remediation Time 2 years
23 SUMMARY OF THE COMPARATIVE ANALYSIS OF ALTERNATIVES
The following analysis evaluates the eight remedial alternatives using the criteria described on the
following page. The purpose of this analysis is to identify the relative advantages and disadvantages of
each alternative. For a more detailed evaluation see the FS for Spill Sites 2,3, and 10.
2.9.1 Threshold Criteria
Overall protection of human health and the environment
All alternatives (except No Action) provide protection for human health and the environment by
implementing institutional controls and monitoring. Under current use conditions, no threats are posed by
subsurface soil and groundwater contamination because there is no actual exposure.
Alternatives GW2C, GW4C, GW5C, and GW6 have less long-term risk because these alternatives reduce
remediation time in treated areas. Alternatives GW2A and GW3C require longer remediation times.
However, the reduction in risk as a result of shorter remediation time is marginal because modeling
performed during the FS shows contamination is not expected to migrate to any drinking water wells or the
Mad River.
WPAFB Draft Record of Decision for Spill Sites 2,3 and 10 33
-------
Wright-Patterson AFB first considered a preliminary range of alternatives consisting of different process options that could
reduce the risks to the public and the environment. Some of the alternatives evaluated during initial screening were
eliminated as a result of implementability concerns, lack of effectiveness, or excessive costs.
Threshold Criteria (alternatives must meet these)
Overall Protection of Human Health and the Environment addresses how an alternative provides
adequate protection of human health and the environment and how risks posed through each exposure pathway are
eliminated, reduced, or controlled through treatment, engineering controls, or institutional controls.
Compliance with Applicable or Relevant and Appropriate Requirements (ARARs) addresses whether an
alternative will meet Federal and state ARARs. ARARs are regulations or other legal requirements that may govern
environmental actions at a particular site.
Balancing Criteria (used to optimize the selection)
Long-Term Effectiveness and Permanence addresses the effectiveness of an alternative to maintain
protection of human health and the environment after remedial objectives have been achieved.
Reduction of Toxicity, Mobility or Volume through Treatment addresses the expected performance of the
alternative or technology to permanently and significantly treat the hazardous substances.
Short-Term Effectiveness addresses the time frame to complete the remedial action and any adverse
impacts to human health and the environment that may occur during the implementation and operation period until remedial
objectives are achieved.
Implementability is the technical and administrative feasibility of a remedy, including the availability of
materials and services needed to implement.
Cost includes capital and operations and maintenance costs, as well as a present worth cost. Present worth
is the total cost of an alternative in terms of today's dollars.
Modifying Criteria (used to finalize the alternative) *"""
State Acceptance indicates the concerns the state has regarding the selected remedy. This
criterion is assessed following comment by state regulatory agencies on the RI/FS Reports and the Proposed Plan.
Community Acceptance indicates the concerns the public may have regarding each of the alternatives.
This criterion is assessed in the Record of Decision following review of public comments on the RI/FS Report and the
Proposed Plan.
WPAFB Draft Record of Decision for Spill Sites 2,3 and 10
-------
Compliance with all state and federal regulations
All alternatives (except No Action) would meet ARARS. All remediation methodologies are expected to
reach the federal MCL for benzene in groundwater and the State of Ohio's underground storage tank
criterion for BTEX. The only difference among the alternatives is the tune required to meet these levels;
active treatments will take approximately 2 to 7 years and natural attenuation of groundwater and in situ
treatment of subsurface soil will take 8 years.
The No Action alternative does not meet these threshold criteria and was dropped from further
consideration.
2.93 Primary Balancing Criteria
Long-term effectiveness and permanence
All alternatives provide effective and permanent reduction of existing BTEX contamination in subsurface
soil and benzene contamination in groundwater. Because the success of any of the alternatives to
remediate the POL Storage Area vicinity spill sites depends on the elimination of continuing and future
potential sources of petroleum hydrocarbon contamination, the evaluation of all alternatives assumes
recent upgrades to the POL Storage Area eliminate continuing contamination. If sources are not removed,
remediation systems may need to be operated periodically over the lifetime of the POL facility.
Alternatives providing for active treatment of subsurface soil (GW2B, GW2C, GW4C, GW5C, and GW6)
will accelerate the degradation of BTEX and reduce remediation time in treated areas. Alternatives
GW2A and GW3C rely on natural processes to degrade hydrocarbon contamination in subsurface soil and
require a longer remediation time.
Modeling results have shown that, with no new or continuing significant sources of contamination,
benzene in groundwater will drop below the remediation goal within 2 years by natural processes.
Alternatives providing for active treatment of groundwater either by extraction and treatment (GW3C,
GW4C, GW5C) or in situ air sparging (GW6) will reduce benzene concentrations below the remediation
goal in 1 year.
Reduction of toxicity, mobility, or volume through treatment
All alternatives will reduce toxicity, mobility, or volume through treatment Treatment will be in the form
of either natural, passive, or active processes. All alternatives will reduce BTEX contamination levels in
subsurface soil and benzene levels in groundwater. These reductions will cause changes in groundwater
chemistry and decrease metals mobility. Reduction in mobility and toxicity for volatile hydrocarbons in
the subsurface soil will be accelerated by alternatives using active treatment systems such as soil
bioventing or soil vapor extraction.
Short-term effectiveness
All alternatives provide immediate protection through existing institutional controls. Periodic monitoring
will verify the status of residual contamination and therefore protect future receptors before exposure.
No risks are posed to the community during remediation or construction activities from any of the
alternatives. Alternatives GW3C, GW4C, and GW5C do pose some risks to workers handing residuals
from the groundwater and treatment process and from the hydrogen peroxide chemical oxidizer.
WPAFB Draft Record of Decision for Spill Sites 2,3 and 10 34
-------
Alternative GW2A poses the least risk to workers because it has the fewest worker requirements and less
potential for exposure.
Implementability
All alternatives use common equipment, common materials, and reliable technologies. Hie easiest
alternative to implement is GW2A because it has the fewest requirements. Areas directly under the active
bermed Tank Farm are considered to be inaccessible to all active remedial technology options.
Cost
The cost difference between the alternatives is significant and varies by more than an order of magnitude.
Alternative GW2A would be the least costly to implement because it has the lowest capital costs and
annual O&M cost. The differences in costs among Alternatives GW2A, GW2B, and GW2C reflect the
cost associated with different soil treatments. Alternatives GW3C, GW4C, and GWSC include
groundwater extraction and treatment and are the most costly alternatives.
Modifying Criteria
Regulatory acceptance
The USEPA and the State of Ohio have reviewed the alternatives and are in agreement with the selected
remedy.
Public acceptance
WPAFB solicited input from the public during the RI and Proposed Plan for Spill Sites 2, 3, and 10 at
OU 2. The Proposed Plan was made available to the public in the Administrative Record and the
Information Repository. A public comment period was held from February 24 through March 25, 1997.
The public comment period was not extended as there were no requests for an extension. The Base held a
public meeting on March 4, 1997, at 6:00 p.m. to discuss the proposed remedy for the Spill Sites. No
members of the public attended the meeting and no written comments were received.
2.10 THE SELECTED REMEDY
The selected remedy for cleanup of groundwater and subsurface soil at Spill Sites 2, 3, and 10 in the POL
Storage Area vicinity is Alternative GW2A:
• in situ biodegradation of contaminants in subsurface soil,
• natural attenuation of contaminants in groundwater,
• O&M of existing recovery actions,
• institutional controls, and
• subsurface soil and groundwater monitoring.
WPAFB Draft Record of Decision for Spill Sites 2,3 and 10 35
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The reasoning to support the selected remedial action for soil and groundwater contamination at the POL
Storage Area vicinity sites is summarized as follows.
• Recent upgrades to the POL facility (abandonment of the underground piping and new geotextile liner
in the bermed Tank Farm) act as a source control measure by essentially eliminating the risk of any
undetected fuel leaks.
• The inconsistent occurrence of free product, coupled with the limited amount of free product recovered
to date, indicates a system built to recover free product beyond that being addressed by existing
recovery actions is unwarranted.
• Geotechnical data collected at the site and modeling performed during the FS indicate groundwater
underneath the spill sites has the capacity to biodegrade the hydrocarbons currently in the system
before a potential receptor, a drinking water well for example, can be reached.
• The monitoring program will verify the status of the residual soil and groundwater contamination and
therefore protect future receptors before exposure.
• No treatment by-products (e.g., spent carbon and sludges) would be produced and no hazardous
chemicals (e.g., oxidizing agents) need to be stored on site.
• Institutional controls are already in place to limit access to or use of the sites.
• GW2A is projected to be, by far, the most cost-effective alternative to accomplish the remedial action
objectives.
The monitoring program is currently being developed under the BMP in consultation with OEPA and
USEPA. WPAFB has worked with OEPA and USEPA to determine sampling frequency, sampling
locations, and the list of analytes.In May 1997 WPAFB conducted additional groundwater, soil gas and
soil sampling to evaluate the effectiveness of in-situ biodegradation and natural attenuation processes
within the area of OU2. The results of that sampling indicated that natural processes are effectively
degrading the hydrocarbon contamination in both subsurface soils and groundwater. As Alternative
GW2A is implemented, the monitoring program will provide the data necessary to verify that in situ
biodegradation of subsurface soils and natural attenuation of groundwater continues to effectively address
the hydrocarbon contamination at these sites. If subsequent monitoring under the BMP indicates that
natural attenuation is no longer effective, active measures will be implemented at these sites.
2.11 STATUTORY DETERMINATION
Based on consideration of the requirements of CERCLA, the comparative analysis, and public comments,
WPAFB, USEPA, and the State of Ohio believe Alternative GW2A provides the best balance of trade-offs
among the alternatives with respect to the criteria used to evaluate remedies. The selected remedy is
consistent with CERCLA and, to the extent practicable, the NCP. The selected remedy is protective of
human health and the environment, complies with federal and state requirements that are legally
applicable or relevant and appropriate to the remedial action, is cost-effective, and uses permanent
solutions and alternative treatment to the maximum extent practicable. The selected remedy satisfies the
statutory preference for treatment as a principal element even though the treatment occurs passively and
naturally.
2.11.1 The Selected Remedy is Protective of Human Health and the Environment
The selected remedy, Alternative GW2A, will reduce the risk of exposure to contaminants by
implementing access restrictions, institutional controls, and monitoring. No threats are posed by the
current subsurface soil and groundwater contaminants under current use conditions. Access restrictions
WPAFB Draft Record of Decision for Spill Sites 2.3 and 10 36
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are currently in force because of the nature of site activities (i.e., active military base, aircraft movement
and operations, and presence of fuel products). Institutional controls such as fences and deed restrictions
ensure that access to the site is restricted and future land use is appropriate. Signs will be installed to
warn of the potential risks associated with exposure to subsurface SOU and groundwater contaminants. No
unacceptable risks or cross-media impacts will be caused by implementing Alternative GW2A because no
contaminated materials will be exposed by this technology. During any site intrusive activities, clearances
will be obtained from the appropriate Base office. Workers and site personnel will be instructed in site
hazards and use of personal protective equipment.
2.112 The Selected Remedy Complies with Applicable or Relevant
and Appropriate Requirements
Hie selected remedy will comply with chemical-specific, action-specific, and location-specific ARARs
and is consistent with U.S. Air Force policy to use in situ biodegradation and natural attenuation whenever
feasible. BTEX levels in subsurface soil will be reduced to levels below the criteria set by the State of
Ohio's BUSTR. Benzene concentrations will be reduced below the MCL of 5 ug/L, as specified by the
USEPA Safe Drinking Water Standards and Ohio Drinking Water Rules.
There will be no adverse impact to the environment because site disturbance will be minimal. No
environmentally sensitive areas, wetlands, rivers, or streams will be impacted by this alternative.
The monitoring program will meet NCP requirements.
2.1 U The Selected Remedy is Cost Effective
The selected remedy is cost effective (i.e., the remedial action affords overall effectiveness proportional to
its cost). The estimated present worth is $610,000, the lowest present worth of all alternatives except the
No Action alternative.
2.11.4 The Selected Remedy Uses Permanent Solutions and Alternative
Treatment Technologies to the Maximum Extent Practicable
The selected remedy, Alternative GW2A, is a permanent solution that uses alternative treatment
technologies to the maximum extent practicable. The statutory preference for treatment as a principle
element was found to be unnecessary because (1) data indicate groundwater beneath the spill sites has the
capacity to biodegrade the hydrocarbons before a potential receptor can be reached and (2) institutional
controls are already in place to prevent exposure to subsurface soil.
The reliance of natural attenuation mechanisms for the cleanup of petroleum-contaminated media has
been demonstrated at various sites around the country to be cost effective and, if properly monitored, an
environmentally sound resolution to petroleum hydrocarbon contamination. It results in permanent
reduction in the mobility, toxicity, and volume (concentrations) of the contaminants in subsurface soils
and groundwater. Investigative data show these processes are already at work within the site area.
WPAFB Draft Record of Decision for Spill Sites 2,3 and 10 37
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2.12 DOCUMENTATION OF NO SIGNIFICANT CHANGES
The Proposed Plan for Spill Sites 2,3, and 10 was released for public comment in February 1997 and a
public meeting was held on March 4,1997. The Proposed Plan identified Alternative GW2A (in situ
biodegradation of subsurface soil, natural attenuation of groundwater, O&M of existing removal actions,
institutional controls, and subsurface soil and groundwater monitoring) as the most appropriate remedial
action.
No written or verbal comments were received from the public; therefore, no significant changes to the
selected remedy are required.
WPAFB Draft Record of Decision for Spill Sites 2,3 and 10 38
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APPENDIX A
Administrative Record
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DOCUMENTS FOUND IN THE ADMINISTRATIVE RECORD FILE RELATING TO SPILL
SITES 2,3, AND 10
TITLE: Installation Restoration Program, Final Report, Phase II Stage I - Study
MICROFICHE*: M-C1 SITE CODE: Multiple FILE STRUCTURE: Cl
AUTHOR: Roy F. Weston, Inc.
DOCUMENT DATE: lSep85 DATE ENTERED: 8Nov89
TITLE: Installation Restoration Program, Phase II Stage 2 - Technical Operations Plan
MICROFICHE #: M-C2a SITE CODE: Multiple FILE STRUCTURE: C2a
AUTHOR: Roy F. Weston, Inc.
DOCUMENT DATE: 1 Oct 86 DATE ENTERED: 8 Nov 89
TITLE: Preliminary Assessment - Spill Site 2
MICROFICHES: SPILL2-E1 SITE CODE: SPILL2 FILE STRUCTURE: El
AUTHOR: Engineering-Science
DOCUMENT DATE: 16 May 88 DATE ENTERED: 8 Nov 89
TITLE: Preliminary Assessment - Spill Site 3
MICROFICHES: SPILL3-E1 SITE CODE: SPILLS FILE STRUCTURE: El
AUTHOR: Engineering-Science
DOCUMENT DATE: 16 May 88 DATE ENTERED: 8 Nov 89
TITLE: Phase II Stage 2 - Work Plan for the Installation Restoration Program
MICROFICHE #: M-C2d SITE CODE: Multiple FILE STRUCTURE: C2d
AUTHOR: Roy F. Weston, Inc.
DOCUMENT DATE: 1 Aug 88 DATE ENTERED: 8 Nov 89
TITLE: Phase II Stage 2 - Health and Safety Plan for the Installation Restoration Program
MICROFICHES: M-C2b SITE CODE: Multiple FILE STRUCTURE: C2b
AUTHOR: Roy F. Weston, Inc.
DOCUMENT DATE: I Aug 88 DATE ENTERED: 8 Nov 89
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TITLE: Phase II Stage 2 - Quality Assurance Project Plan for the Installation Restoration Program
MICROFICHE*: M-C2c SITE CODE: Multiple FILE STRUCTURE: C2c
AUTHOR: Roy F. Weston, Inc.
DOCUMENT DATE: 1 Aug 88 DATE ENTERED: 8Nov89
TITLE: Comprehensive Work Plan for the Installation Restoration Program at Wright-Patterson AFB
MICROFICHE #: M-A SITE CODE: Multiple FILE STRUCTURE: A
AUTHOR: 2750 ABW/EM WPAFB
DOCUMENT DATE: 1 Jun 89 DATE ENTERED: 8 Nov 89
TITLE: Installation Restoration Program Phase II Stage 2 Report
MICROFICHE #: M-C2a-m SITE CODE: Multiple FILE STRUCTURE: C2a-m
AUTHOR: Roy F. Weston, Inc.
DOCUMENT DATE: Uul89 DATE ENTERED: 8 Nov 89
TITLE: Preliminary Assessment - Spill Site 10
MICROFICHE*: SPILL10-E1 SITE CODE: SPILL 10 FILE STRUCTURE: El
AUTHOR: 2750 ABW/EM WPAFB
DOCUMENT DATE: 21 Nov 89 DATE ENTERED; >4Dec90
TITLE: Final Site Inspection Project Work Plan for 17IRP Sites
MICROFICHE*: M-Fla-b SITE CODE: Multiple FILE STRUCTURE: Fla-b
AUTHOR: Hazardous Waste Remedial Actions Program Martin Marietta Energy Systems, Inc.
DOCUMENT DATE: I Jun 90 DATE ENTERED: 24 Jul 91
TITLE: Remedial Investigation/Feasibility Study Work Plan for 39 Sites (with amendments)
MICROFICHE*: M-I1 SITE CODE: Multiple FILE STRUCTURE: II
AUTHOR: Engineering-Science
DOCUMENT DATE: 30 Jun 90 DATE ENTERED: 3 Mar 93
TITLE: Free Product Recovery Well Work Plan at Spill Sites 2 and 3 (Skimmer Pump)
MICROFICHE*: SPILL2,3-G2a SITE CODE: SPILL 2.3 FILE STRUCTURE: C2a
AUTHOR: Petro Environmental Tech
DOCUMENT DATE: 21 Feb 91 DATE ENTERED: 4 Jun 91
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TITLE: Free Product Recovery Project Final Report (Skimmer Pump)
MICROFICHE #: SPILL2,3-G2b SITE CODE: SPILL 2, 3 FILE STRUCTURE: G2b
AUTHOR: Petro Environmental Tech
DOCUMENT DATE: 19 Apr 91 DATE ENTERED: 4 Jun 91
TITLE: Analysis of Soil Gas Survey Results for Spill Sites 2 and 3
MICROFICHE #: SPILL2,3-I2a SITE CODE: SPILL 2.3 FILE STRUCTURE: I2a
AUTHOR: Engineering-Science
DOCUMENT DATE: Uul91 DATE ENTERED: 20 Nov 91
TITLE: Free Product Recovery Health and Safety Plan Volume II (Dual Pump)
MICROFICHE #: SPILL2,3-G2d SITE CODE: SPILL2.3 FILE STRUCTURE: G2d
AUTHOR: OHM Corp
DOCUMENT DATE: 6 Dec 91 DATE ENTERED: 24 Nov 92
TITLE: Free Product Recovery Work Plan (Volume I) - Dual Pump
MICROFICHES: SPILL2.3-G2c SITE CODE: SPILL 2,3 FILE STRUCTURE: G2c
AUTHOR: OHM Corporation
DOCUMENT DATE: 29 Jan 92 DATE ENTERED: 25 Mar 92
TITLE: Field Sampling Plan for the Remedial Investigation/Feasibility Study at Operable Unit 2
(Northeastern Area)
MICROFICHES: M-I4(OU2) SITE CODE: Multiple FILE STRUCTURE: 14 (OU2)
AUTHOR: Engineering-Science
DOCUMENT DATE: 30 Jun 92 DATE ENTERED: 3 Mar 93
TITLE: Site Investigation Report for 16IRP Sites
MICROFICHE*?: M-F2 SITE CODE: Multiple FILE STRUCTURE: F2
AUTHOR: SAIC
DOCUMENT DATE: 30 Mar 93 DATE ENTERED: 2 Sep 93
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TITLE: Free Product Recovery Project Final Report, Operations and Maintenance Plan, and As-Built
Drawings
MICROFICHE #: SPILL2.3-G3 SITE CODE: SPILL 2. 3 FILE STRUCTURE: 03
AUTHOR: OHM
DOCUMENT DATE: 7 Apr 94 DATE ENTERED: 19Sep94
TITLE: Final Remedial Investigation Report for Operable Unit 2 (Referenced Sites: Spill Sites 2,3, 10;
Burial Site 1; Coal and Chemical Storage; Temporary Coal Storage; Long-Term Coal Storage Pile;
Building 89 Coal Storage Pile)
MICROFICHE*: SPILL2.3-I5 SITE CODE: SPILL 2,3 FILE STRUCTURE: 15
AUTHOR: Engineering-Science
DOCUMENT DATE: 31 Aug 95 DATE ENTERED: 31 Jan 96
TITLE: Management Action Plan
MICROFICHE #: M-O SITE CODE: Multiple FILE STRUCTURE: O
AUTHOR: CH2MHU1
DOCUMENT DATE: 30 Dec 95 DATE ENTERED: 31 Jan 96
TITLE: Feasibility Study for Spill Sites 2,3.10 Within Operable Unit 2
MICROFICHE #: SPILL2,3,IO-J SITE CODE: Spill 2,3, 10 FILE STRUCTURE: J
AUTHOR: Parsons Engineering Science, Inc.
DOCUMENT DATE: 31 Aug 96 DATE ENTERED: 25 Nov 96
TITLE: Enforcement - Correspondence with Regulatory Agencies
MICROFICHE #: M-L4 SITE CODE: Multiple FILE STRUCTURE: L4
AUTHOR: Air Force and EPA
DOCUMENT DATE: As of I Nov 96 DATE ENTERED: 25 Nov 96
TITLE: Public Participation
\
MICROFICHES: M-N2.5.6 SITE CODE: Multiple FILE STRUCTURE: N2.5.6
AUTHOR: Public/Air Force
DOCUMENT DATE: As of 1 Nov 96 DATE ENTERED: 25 Nov 96
TITLE: Proposed Plan for Remedial Action at Operable Unit 2 Spill Sites 2, 3, and 10
MICROFICHE #: SPILL2.3,IO-H4 SITE CODE: SPILL 2,3,10 FILE STRUCTURE: H4
AUTHOR: Hazardous Waste Remedial Action Program Lockheed Martin Energy Systems. Inc.
DOCUMENT DATE: 28 Feb 97 DATE ENTERED: 21 Feb 97
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APPENDIX B - RESPONSIVENESS SUMMARY
Tlie Proposed Plan for Spill Sites 2,3, and 10 was released for public comment in February 1997 and a
public meeting was held on March 4,1997. The Proposed Plan identified Alternative GW2A (in situ
biodegradation of subsurface soil, natural attenuation of groundwater, O&M of existing removal actions,
institutional controls, and subsurface soil and groundwater monitoring) as the most appropriate remedial
action.
No written or verbal comments were received from the public; therefore, no significant changes to the
selected remedy are required.
WPAFB Draft Record of Decision for Spill Sites 2,3 and 10
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